Background and Aim: The purpose of this study was to investigate the effect of endurance training intensity (low, moderate and high) on the expression of skeletal muscle ATGL protein and serum levels of insulin and glucose in male diabetic rats.Material and Method: 40 streptozotocin induced diabetic male Wistar rats were randomly assigned to five groups of eight, including low (DL , moderate (DM) and high intensity (DH) endurance training diabetic groups, diabetic control group (D), and healthy control group (Con). Three sessions of endurance training with low intensity (DL( equivalent to 5-8 m / min, moderate intensity (DM) equivalent to 17-14 m / min and high intensity (DH) equivalent to 25-22 m / min were performed every week for eight weeks. The relative expression of ATGL protein was measured with western blot technique. Serum insulin and glucose levels were measured by ELISA method. To determine the difference between the groups we used one way ANOVA test.Result: The results showed a significant difference in the expression of ATGL between the control and training groups (with low, moderate and high intensity) (p=0.0002). This difference was significant between DH and D (p=0.0049), DH and DL (p = 0.0053) and also between DH and DM (P = 0.0136) groups. Serum glucose levels were also significantly different between the DH group with the groups D (p = 0.002) and DL (p = 0.039), also, the DM group with groups D (p = 0.0018) and DL (p = 0.0165). There was a significant difference in the amount of insulin in the DH group compared to the groups DL (p = 0.011), D (p = 0.0002), and the DM group with D (p = 0.014).

Conclusion: Moderate and high intensity endurance training can to some extent compensate for diabetes-induced reduction in the expression of ATGL protein and cause reduction of serum insulin and glucose levels in diabetic rats. It seems higher intensity of endurance training can lead to greater increase in expression of ATGL in diabetic rats.Keywords: Diabetes, ATGL, Endurance training intensity, Insulin, Glucose.